Conventional aqueous thermal ink jet or piezo aqueous inks have been found to cause cockle, curl and/or showthrough, which is readily apparent when printing on plain paper, particularly if the amount of water in the ink exceeds 50% by weight. Also, printing on non-porous substrate requires specialized ink formulations with binders incorporated, and drying systems that often limit print speed and increase cost per prints.
A number of approaches have been used to increase the printing latitude of aqueous inks including the use of hydrophobic and/or coagulating undercoat on the substrate. The use of undercoats increases cost and complexity of the printing system and cannot be applied universally to all types of substrates, including plain and coated paper.